New Water-Based Battery Targeted at Renewables

Scientists from Stanford University in the U.S. have developed a manganese-hydrogen battery that could provide a cheap way to store wind or solar energy so it can be fed back into the electric grid and be redistributed when demand is high.

A prototype of the manganese-hydrogen battery stands just three inches tall and generates a mere 20 milliwatt hours of electricity, which is on par with the energy levels of LED flashlights that hang on a key ring. Yet, the researchers are confident they can scale up the technology to an industrial-grade system that could charge and recharge up to 10,000 times, creating a grid-scale battery with a useful lifespan well in excess of a decade.

Yi Cui, a professor of materials science at Stanford, said the battery uses manganese sulfate in water and an electrode to create a reversible chemical reaction that stores electrons in the form of hydrogen gas. The research was led by Wei Chen, a postdoctoral scholar in Cui’s lab.

Cui believes the prototype technology will be able to meet Department of Energy (DOE) goals for utility-scale electrical storage practicality. The DOE has recommended batteries for grid-scale storage should store and then discharge at least 20 kilowatts of power over a period of an hour, be capable of at least 5,000 recharges, and have a useful lifespan of 10 years or more. To make it practical, such a battery system should cost $2,000 or less, or $100 per kilowatt hour.

According to DOE estimates, about 70 percent of U.S. electricity is generated by coal or natural gas plants, which account for 40 percent of carbon dioxide emissions. Shifting to wind, ocean and solar generation is one way to reduce those emissions, and this week U.S. Undersecretary of Energy Mark Menezes announced up to $23 million for innovative technologies to reduce capital costs and shorten deployment timelines of marine energy devices.